Manufacture of fire extinguishers



June 13, 1933. c. FSMITH 1,913,688

, MANUFACTURE OF FIRE EXTINGUISHERS Filed sept. `4, 1931 IN VEN TOR.

W RIM ffm-7' ATTORN YS. n

secured against internal pressure as well as' lPatented June 1.3, 1933 UNITED STATES PATENT OFFICE CARLISLE F. SMITH, 0F ELMIRA, NEW YORK, ASSIGNOR TO AMERICAN -LA FRANCE AND FOAMITE CORPORATION, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK MANUFACTURE OF FIRE EXTINGUISHERS Application led September 4, 1931. Serial No. 561,13?.

The invention refers to an economical process for 'manufacturing fire extinguishers, and more particularly for connecting the neck ring to the body or shell of the extinguisher. It consists in the successive steps herein described and in the extinguisher resulting therefrom having an 1mproved joint between neck ring and body against weakening by corrosion.

Referring to the drawing Fig. 1 1s a central vertical section through the neck ring and the body or shell of the extin- 4guisher showing the parts ready for assembling. Fig. 2 is a view corresponding to Fig. 1 with the ring seated on the shell, and Fig. 3 is a similar view showing the completed joint.

The main shell of the extinguishermarked 1 is` first provided with a cylindrical projecting rim 2 bossed outwardly therefrom at the top ofitsI dome portion. The shell is then tinned that is coated throughout its entire interior with a coating a of solder metal to avoid corrosion by chemicals and this coatin is made to extend on to and around `an on the outside of the bossed rim. The neck ring 4, cast or forged and provided with an inward ange 5, and having an undercut machined groove G oni'ts inner side, is then also coated with solder metal, all over fas by dipping it, as indicated at a. This ring is then externally threaded 'at 7 and its top surface dressed of to form a gasket seat 8.. The coated bossed rim is introduced -into it (Fig. 2) and expanded into the undercut groove so as to interlock therewith (Fig. 3). The joint thus formed is then heated so'as to fuse the two contiguous coatings and improve the bond of the interlock, at the same time efl'ectually excluding entrance of any of the chemical contents ofthe extinguisher finto the crevice between rim and ring which might corrode and either weaken the joint or produce a leak. A small band of solder 9 may, if desired, be inserted inthe depression between the' rim and the ring after it has been pressed intoplace and before heating.

`enables the soldering to be done from the outside of the shell .rather/than through the bottom end of the shell and is advantageous in the particular and specific fire extinguisher art.

I claim:

l. The process of making a fire extinguisher which consists in first forming a main shell with an outwardly bossed rim, coating the whole of the interior of the shell and the outside of therim with solder metal, locating the neck ring exterior to the main shell and bossed rim and expanding suph rim into an undercut groove in the in* ner side of the neck ring, then heating the joint thus formed to fuse the contiguous surfaces'thereof.

2. The process of making a, fire extinguisher which consists in first forming a main "shell with an outwardly bossed rim, coating the whole of the interior of the shell and the outside'of the rim with solder metal, coating, by dripping., the whole of the neck ring into solder metal, l cat-ing the neck ring exterior to the main s ell and bossed rim and expanding such rim into an undercut groove in the inner side of the neck ring, then heating the joint thus 'formed to fuse the contiguous surfaces thereof.

3. A ire extinguisher comprising an external neck ring having an inward flange and an undercut internal groove below the flange, a main shell having a bossed rim outwardly bent into interlocking engagement with the undercut groove and having a layer of solder metal intervening between the rim and ring adapted to exclude entrance of chemical into the crevice therebetween and secure against internal pressure.

4. The process of making a re extinguisher which consists in forming a main shell with an outwardly bossed rim, coating said rim outside and inside with solder metal, forming a neck ring having an inward fiange and an undercut internal groove below the flange, coating-the interior of the ring with solder metal, expanding the bossed rim of the shell outwardly into interlock ing engagement .with the undercut groove 4guisher which consists in in the neck ring, and then heating the joint thus formed to fuse the solder metgl intervening between the rim and ring to exclude entrance of chemical into the crevice therebetween.

5. The process of makin a lire extinrst ,forming a main shell with anoutwardly bossed rim, coating the whole of the interior of the shell and the outside of the rim with solder metal, causing the neck ring to seat on the shell exterior to and adjacent thebossed rim and expanding such rim into an undercut groove in the inner side of the neck ring, inserting a bandA of solder into the depres sion between lthe rim and the ring, then heating the joint thus. formed to fuse the contiguous surfaces thereof.

In testimony whereof, I have signed this specification. y

j CARLISLE F. SMITH. 

